Flexible face signs of the type related to the present invention have their face material stretched across an opening in a sign frame and anchored to the periphery of the sign's opening. Holding devices are attached at intervals along the face material and are generally made to engage into a slot along the sign frame or casing to affix the face material to the casing. The holding devices and the slot are covered with a cap or molding that enhances the general appearance of the sign. These corner caps or moldings, hereinafter referred to as sign edging, are commonly held to the sign flame with screws, or by an interlocking engagement of mating lips and grooves.
Examples of sign edging of the prior art are disclosed in U.S. Pat. No. 5,255,459 issued on Oct. 26, 1993, and in U.S. Pat. No. 5,669,166, issued on Sep. 23, 1997, both to Normand Verret, the inventor of the present invention. In these inventions, the edging clips in place over a sign frame and is held there by the interference of two pairs of opposing lips.
Various other types of sign edging are known in the art, and for reference purposes, other examples of sign edging of the prior art are disclosed in U.S. Pat. No. 5,301,447 issued on Apr. 12, 1994 to H. R. Lotter et al, and in U.S. Pat. No. 5,647,155 issued on Jul. 15, 1997 to D. U. Hillstrom.
In both the latter-mentioned structures, it is believed that the sign edging must be deformed slightly to engage onto retaining lips on the sign casing. The installation requires applying pressure from two directions in order to clip the edging in place. A sign edging of the prior art is typically installed by pushing or pulling it in a direction perpendicular to the sign face, and by simultaneously twisting or pressing it in a direction tangential to the sign face.
These movements are not always readily understood by tradespeople. These movements require some training which is not always available to the one-time subcontractor installing a sign of that type, or to the maintenance person tending to the sign therafter. As a result, the edging is often improperly removed causing damage to the engaging lips, or is not properly re-installed, leading to premature deterioration of the sign.